In this type of vehicle seat, a stitch portion (linear seam) is formed to a seat cover. This stitch portion appears on a design surface of the seat cover, thereby constituting a part of the design of the seat. For example, a seat cover disclosed in JP-A-2006-117092 is formed by sewing a plurality of skin pieces and has a double stitch portion including a pair of stitch portions. In this seat cover, adjacent ends of the skin pieces are turned back inwardly and sewn to each other. Distal end portions of respective skin pieces are folded inward with a sewing place serving as a boundary and are sewn to the corresponding skin piece. A pair of stitch portions is formed by thread materials for sewing the distal ends of respective skin pieces. The pair of stitch portions appears on a design surface of the seat cover. At this time, the pair of stitch portions extends in parallel across the border of the adjacent skin pieces, thereby forming the double stitch portion.
In this type of configuration, a pair of stitch portions is often arranged in parallel at one side of an institch portion. At this time, seams of thread materials constituting one of the stitch portions are intermittently arranged, when viewed in an extending direction of the stitch portions. Similarly, seams of thread materials constituting the other of the stitch portions are arranged side by side in parallel with the seams of the thread materials constituting one of the stitch portions. Here, when viewed in a direction perpendicular to the extending direction of each stitch portion, a place where a pair of seams is arranged in parallel and a place where no seam is arranged are alternately formed on the portion of the seat cover at which the double stitch portion is disposed. The portion of the seat cover at which no seam is arranged is easily deformed and twisted, as compared to the portion of the seat cover which is constrained by the formation of the seams. Therefore, in the configuration of the related art, lateral wrinkles in the direction perpendicular to the extending direction of the double stitch portion occur in the place where the seam of the double stitch portion is not provided. Accordingly, there is a risk that the appearance of the seat cover is deteriorated.